These are 1960s and more of the story about these is within the next page. Click "Previous". I have been told it has been (unusual) practice to use these in special colors to mark different primary voltages deadending on the same pole for safety purposes years ago. Others within the collection these came from were in shades of green, orange, yellow, etc. and in numerous designs, different mqanufacturers, etc. I have no more info about these nor who they were sold to. But thanks to Jill M. (my Jill, not Bill's ;-) to whom any or all of these were offered (she declined) we are able to see some colorful non-glass, non-porcelain line wire insulators.